Units

Model units properties manage the units settings for the current model space.

Layout units properties manage the layout units for the current layout space.

Units and tolerances

Model units

Controls the units used in the model.

Layout units

Controls the units used in the layouts.

When you change from one units system to another, Rhino asks if you want to have the geometry automatically scaled to match the unit change.

Hatch patterns are automatically scaled when units change.

Absolute tolerance

Tolerance in units used when creating new geometry that cannot be absolutely accurate. For example, trimming surfaces, doing offsets and Boolean operations usually create approximate geometry.

Angle tolerance

Sets the angle tolerance in some commands use to create, modify, or evaluate geometry.

When creating or modifying geometry the angle between two objects will be less than or equal to the tolerance value.

Two objects will meet an evaluation criterion, such as tangency, when the angle between them is less than the tolerance value.

Understanding Tolerances

Custom units

Name

The unit name.

Units per meter

Enters a scale in units per meter.

Distance display

Sets the distance display for the status bar and distance and length commands.

Decimal

Sets the display to decimal (1.25).

Fractional

Sets the display to fractional (1-1/4).

Feet & Inches

Sets the display to feet and inches (1'-3").

Display precision

Sets the number of decimal places for the distance display.

Note

• It is best to select a tolerance when you start modeling and stick with it.
• Importing a model in a format that supports units and tolerance will not adjust Rhino's units or tolerances. A dialog box will warn you if the units do not match.
• The following three items are a good guide to choosing tolerance.
• Rhino can work in any unit system and with any tolerance. The default unit system is millimeters, and the default tolerance is 0.01 millimeters. You can change the default unit system or tolerance by setting up a template. If you frequently need to work in more than one unit system or with more than one tolerance, set multiple templates.
• In general, Rhino works best if you choose a unit system whose absolute tolerance is around 0.01 to 0.001, the "size" of a small feature (like a tiny fillet or small curve offset distance) is >= 10 x tolerance, and the "size" of the model is <= 100000.
• Using an absolute tolerance that is smaller than 0.0001 will noticeably slow some intersection and fitting processes.

Distance units

Use any of the Rhino unit measurements including fractions. You can mix fractional and decimal input.

Microns

1.2mic

1.2micron(s)

Millimeters

1.2mm

1.2millimeter(s)

Centimeters

1.2c

1.2cm

1.2centimeter(s)

Meters

1.2m

1.2meter(s)

Kilometers

1.2km

1.2kilometer(s)

Microinches

1.2microinch(es)

Mils

1.2mil(s)

Feet and Inches

1"

1in

1inch(es)

1'2-1/2(")

1'2.2(")

1-1/2"

1.5"

1'

1ft

1foot

1feet

Miles

1mi

1mile(s)

Other

Angstrom

Nanometer

Decimeter

Dekameter

Hectometer

Megameter

Gigameter

Yard

Printer point

Printer pica

Nautical mile

Astronomical unit

Lightyear

Parsec

Angle units

Use any of the Rhino angle unit measurements including fractions. You can mix input types.

The direction for 0 degrees is 3 o'clock. Positive angular measurement is counterclockwise.

Decimal Degrees

The "°" symbol can be used, but it is easier to just type d.

45 (If no units are specified, then degrees are assumed.)

45°

45d

39deg

22.875degs

12.345e2degree

180degrees

47.653395°

Degrees/minutes/seconds

128d37'22"

128°37'22"

99d37'45.234"

32.543'

32'30.1234"

Radians (1πr=180°)

3.1415926535897932384626433832795r (pi radians)

1.234r

1.234rad

1.234rads

1.234radian

1.234radians

Gradians (100g=90°)

4.00g

4.00grad

4.00grads

Surveyor's units

S47°39'08.54"E

See also

Manage document properties

Measure objects